Method of manufacturing magnetic head and method of manufacturing magnetic head substructure

Abstract

A method of manufacturing a magnetic head includes the steps of: fabricating a substructure in which pre-head portions are aligned in a plurality of rows by forming components of a plurality of magnetic heads on a single substrate; and fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure. In the step of fabricating the substructure, the resistance of an MR film that will be formed into an MR element by undergoing lapping later is detected to determine the target position of the boundary between a track width defining portion and a wide portion of a pole layer based on the resistance detected, and the pole layer is thereby formed. In the step of fabricating the magnetic heads, the surface formed by cutting the substructure is lapped such that the MR film is lapped and the resistance thereof thereby reaches a predetermined value.

1. A method of manufacturing a magnetic head, the magnetic head comprising:
 a medium facing surface that faces toward a recording medium; 
 a magnetoresistive element having an end located in the medium facing surface and reading data stored on the recording medium; 
 a coil that generates a magnetic field corresponding to data to be written on the recording medium; and 
 a pole layer that allows a magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field for writing the data on the recording medium, wherein 
 the pole layer includes: a track width defining portion including a first end located in the medium facing surface and a second end located away from the medium facing surface, and having a width that defines a track width; and a wide portion coupled to the second end of the track width defining portion and having a width greater than that of the track width defining portion, the method comprising the steps of: 
 fabricating a magnetic head substructure in which a plurality of pre-head portions each of which will be the magnetic head later are aligned in a plurality of rows, by forming components of a plurality of magnetic heads on a substrate; and 
 fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure, wherein: 
 the step of fabricating the substructure includes the steps of: 
 forming a magnetoresistive film unlapped that will become the magnetoresistive element by undergoing lapping later; 
 detecting a resistance of the magnetoresistive film unlapped; 
 determining a target position of a boundary between the track width defining portion and the wide portion of the pole layer based on the detected resistance of the magnetoresistive film unlapped; and 
 forming a pre-lapping pole layer that includes the track width defining portion unlapped and the wide portion and that will become the pole layer by undergoing lapping of the track width defining portion later, the pre-lapping pole layer being formed such that an actual position of the boundary between the track width defining portion and the wide portion coincides with the target position, 
 the step of fabricating the magnetic heads includes the step of forming the medium facing surface by performing lapping of a surface formed by cutting the substructure; 
 in the step of forming the medium facing surface, the lapping of the surface formed by cutting the substructure includes lapping the magnetoresistive film and the track width defining portion of the pre-lapping pole layer simultaneously, and the lapping is performed such that the resistance of the magnetoresistive film reaches a predetermined value; and 
 as a result of the lapping, the magnetoresistive film becomes the magnetoresistive element and the pre-lapping pole layer becomes the pole layer. 
 
     
     
       2. The method according to  claim 1 , wherein, in the step of detecting the resistance of the magnetoresistive film unlapped, the resistance of the magnetoresistive film unlapped is detected while a magnetic field is applied to the magnetoresistive film unlapped. 
     
     
       3. The method according to  claim 1 , wherein:
 the magnetoresistive film includes: a pinned layer having a fixed direction of magnetization; a free layer having a direction of magnetization that changes in response to an external magnetic field; and a spacer layer disposed between the pinned layer and the free layer; and, 
 in the step of detecting the resistance of the magnetoresistive film unlapped, the resistance of the magnetoresistive film unlapped is detected with the direction of magnetization of the free layer rendered parallel to the direction of magnetization of the pinned layer by applying a magnetic field to the magnetoresistive film unlapped. 
 
     
     
       4. The method according to  claim 1 , wherein:
 the step of fabricating the substructure further includes the step of forming a resistor element having a resistance that changes in correspondence with the resistance of the magnetoresistive film in the step of forming the medium facing surface; and 
 in the step of forming the medium facing surface, the lapping is performed such that the resistance of the magnetoresistive film reaches the predetermined value by monitoring the resistance of the resistor element. 
 
     
     
       5. The method according to  claim 4 , wherein the resistance of the resistor element in the step of forming the medium facing surface has a correspondence with a distance between the surface being lapped and the boundary between the track width defining portion and the wide portion. 
     
     
       6. A method of manufacturing a magnetic head, the magnetic head comprising:
 a medium facing surface that faces toward a recording medium; 
 a magnetoresistive element having an end located in the medium facing surface and reading data stored on the recording medium; 
 a coil that generates a magnetic field corresponding to data to be written on the recording medium; and 
 a pole layer that allows a magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field for writing the data on the recording medium, wherein 
 the pole layer includes: a track width defining portion including a first end located in the medium facing surface and a second end located away from the medium facing surface, and having a width that defines a track width; and a wide portion coupled to the second end of the track width defining portion and having a width greater than that of the track width defining portion, the method comprising the steps of: 
 fabricating a magnetic head substructure in which a plurality of pre-head portions each of which will be the magnetic head later are aligned in a plurality of rows, by forming components of a plurality of magnetic heads on a substrate; and 
 fabricating the plurality of magnetic heads by separating the pre-head portions from one another through cutting the substructure, wherein: 
 the step of fabricating the substructure includes the steps of: 
 forming a magnetoresistive film unlapped that will become the magnetoresistive element by undergoing lapping later; 
 detecting a value of a parameter having a correspondence with a resistance of the magnetoresistive film unlapped; 
 determining a target position of a boundary between the track width defining portion and the wide portion of the pole layer based on the value of the parameter detected; 
 forming a pre-lapping pole layer that includes the track width defining portion unlapped and the wide portion and that will become the pole layer by undergoing lapping of the track width defining portion later, the pre-lapping pole layer being formed such that an actual position of the boundary between the track width defining portion and the wide portion coincides with the target position, 
 the step of fabricating the magnetic heads includes the step of forming the medium facing surface by performing lapping of a surface formed by cutting the substructure; 
 in the step of forming the medium facing surface, the lapping of the surface formed by cutting the substructure includes lapping the magnetoresistive film and the track width defining portion of the pre-lapping pole layer simultaneously, and the lapping is performed such that the resistance of the magnetoresistive film reaches a predetermined value; and 
 as a result of the lapping, the magnetoresistive film becomes the magnetoresistive element and the pre-lapping pole layer becomes the pole layer. 
 
     
     
       7. The method according to  claim 6 , wherein:
 the step of fabricating the substructure further includes the step of forming a detection element having a resistance-area product equal to that of the magnetoresistive film unlapped; and 
 in the step of detecting the value of the parameter, a value of the resistance-area product of the detection element is detected as the value of the parameter. 
 
     
     
       8. The method according to  claim 7 , wherein, in the step of detecting the value of the resistance-area product of the detection element, the value of the resistance-area product of the detection element is detected while a magnetic field is applied to the detection element. 
     
     
       9. The method according to  claim 7 , wherein:
 each of the magnetoresistive film and the detection element includes: a pinned layer having a fixed direction of magnetization; a free layer having a direction of magnetization that changes in response to an external magnetic field; and a spacer layer disposed between the pinned layer and the free layer; and 
 in the step of detecting the value of the resistance-area product of the detection element, the value of the resistance-area product of the detection element is detected with the direction of magnetization of the free layer rendered parallel to the direction of magnetization of the pinned layer by applying a magnetic field to the detection element. 
 
     
     
       10. The method according to  claim 6 , wherein:
 the step of fabricating the substructure further includes the step of forming a resistor element having a resistance that changes in correspondence with the resistance of the magnetoresistive film in the step of forming the medium facing surface; and 
 in the step of forming the medium facing surface, the lapping is performed such that the resistance of the magnetoresistive film reaches the predetermined value by monitoring the resistance of the resistor element. 
 
     
     
       11. The method according to  claim 10 , wherein the resistance of the resistor element in the step of forming the medium facing surface has a correspondence with a distance between the surface being lapped and the boundary between the track width defining portion and the wide portion. 
     
     
       12. A method of manufacturing a magnetic head substructure used for manufacturing a magnetic head, the magnetic head comprising:
 a medium facing surface that faces toward a recording medium; 
 a magnetoresistive element having an end located in the medium facing surface and reading data stored on the recording medium; 
 a coil that generates a magnetic field corresponding to data to be written on the recording medium; and 
 a pole layer that allows a magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field for writing the data on the recording medium, wherein: 
 the pole layer includes: a track width defining portion including a first end located in the medium facing surface and a second end located away from the medium facing surface, and having a width that defines a track width; and a wide portion coupled to the second end of the track width defining portion and having a width greater than that of the track width defining portion; and 
 the substructure is one in which a plurality of pre-head portions each of which will be the magnetic head later are aligned in a plurality of rows, and the substructure is to be cut later so that the plurality of pre-head portions will be separated from one another and so that the medium facing surface will be formed by lapping a surface formed by cutting the substructure, 
 the method of manufacturing the substructure comprising the step of forming components of a plurality of magnetic heads on a substrate so that the pre-head portions are aligned in a plurality of rows, 
 wherein the step of forming the components of the plurality of magnetic heads includes the steps of: 
 forming a magnetoresistive film unlapped that will be lapped later so that a resistance thereof reaches a predetermined value and that will become the magnetoresistive element; 
 detecting the resistance of the magnetoresistive film unlapped; 
 determining a target position of a boundary between the track width defining portion and the wide portion of the pole layer based on the detected resistance of the magnetoresistive film unlapped; and 
 forming a pre-lapping pole layer that includes the track width defining portion unlapped and the wide portion and that will become the pole layer by undergoing lapping of the track width defining portion later, the pre-lapping pole layer being formed such that an actual position of the boundary between the track width defining portion and the wide portion coincides with the target position. 
 
     
     
       13. The method according to  claim 12 , wherein, in the step of detecting the resistance of the magnetoresistive film unlapped, the resistance of the magnetoresistive film unlapped is detected while a magnetic field is applied to the magnetoresistive film unlapped. 
     
     
       14. The method according to  claim 12 , wherein:
 the magnetoresistive film includes: a pinned layer having a fixed direction of magnetization; a free layer having a direction of magnetization that changes in response to an external magnetic field; and a spacer layer disposed between the pinned layer and the free layer; and 
 in the step of detecting the resistance of the magnetoresistive film unlapped, the resistance of the magnetoresistive film unlapped is detected with the direction of magnetization of the free layer rendered parallel to the direction of magnetization of the pinned layer by applying a magnetic field to the magnetoresistive film unlapped. 
 
     
     
       15. The method according to  claim 12 , wherein the step of forming the components of the plurality of magnetic heads further includes the step of forming a resistor element having a resistance that changes in correspondence with the resistance of the magnetoresistive film when lapping is performed on the surface formed by cutting the substructure later. 
     
     
       16. The method according to  claim 15 , wherein the resistance of the resistor element when lapping is performed on the surface formed by cutting the substructure has a correspondence with a distance between the surface being lapped and the boundary between the track width defining portion and the wide portion. 
     
     
       17. A method of manufacturing a magnetic head substructure used for manufacturing a magnetic head, the magnetic head comprising:
 a medium facing surface that faces toward a recording medium; 
 a magnetoresistive element having an end located in the medium facing surface and reading data stored on the recording medium; 
 a coil that generates a magnetic field corresponding to data to be written on the recording medium; and 
 a pole layer that allows a magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field for writing the data on the recording medium, wherein: 
 the pole layer includes: a track width defining portion including a first end located in the medium facing surface and a second end located away from the medium facing surface, and having a width that defines a track width; and a wide portion coupled to the second end of the track width defining portion and having a width greater than that of the track width defining portion; and 
 the substructure is one in which a plurality of pre-head portions each of which will be the magnetic head later are aligned in a plurality of rows, and the substructure is to be cut later so that the plurality of pre-head portions will be separated from one another and so that the medium facing surface will be formed by lapping a surface formed by cutting the substructure, 
 the method of manufacturing the substructure comprising the step of forming components of a plurality of magnetic heads on a substrate so that the pre-head portions are aligned in a plurality of rows, 
 wherein the step of forming the components of the plurality of magnetic heads includes the steps of: 
 forming a magnetoresistive film unlapped that will be lapped later so that a resistance thereof reaches a predetermined value and that will become the magnetoresistive element; 
 detecting a value of a parameter having a correspondence with the resistance of the magnetoresistive film unlapped; 
 determining a target position of a boundary between the track width defining portion and the wide portion of the pole layer based on the value of the parameter detected; and 
 forming a pre-lapping pole layer that includes the track width defining portion unlapped and the wide portion and that will become the pole layer by undergoing lapping of the track width defining portion later, the pre-lapping pole layer being formed such that an actual position of the boundary between the track width defining portion and the wide portion coincides with the target position. 
 
     
     
       18. The method according to  claim 17 , wherein:
 the step of forming the components of the plurality of magnetic heads further includes the step of forming a detection element having a resistance-area product equal to that of the magnetoresistive film unlapped; and 
 in the step of detecting the value of the parameter, a value of the resistance-area product of the detection element is detected as the value of the parameter. 
 
     
     
       19. The method according to  claim 18 , wherein, in the step of detecting the value of the resistance-area product of the detection element, the value of the resistance-area product of the detection element is detected while a magnetic field is applied to the detection element. 
     
     
       20. The method according to  claim 18 , wherein:
 each of the magnetoresistive film and the detection element includes: a pinned layer having a fixed direction of magnetization; a free layer having a direction of magnetization that changes in response to an external magnetic field; and a spacer layer disposed between the pinned layer and the free layer; and 
 in the step of detecting the value of the resistance-area product of the detection element, the value of the resistance-area product of the detection element is detected with the direction of magnetization of the free layer rendered parallel to the direction of magnetization of the pinned layer by applying a magnetic field to the detection element. 
 
     
     
       21. The method according to  claim 17 , wherein the step of forming the components of the plurality of magnetic heads further includes the step of forming a resistor element having a resistance that changes in correspondence with the resistance of the magnetoresistive film when lapping is performed on the surface formed by cutting the substructure later. 
     
     
       22. The method according to  claim 21 , wherein the resistance of the resistor element when lapping is performed on the surface formed by cutting the substructure has a correspondence with a distance between the surface being lapped and the boundary between the track width defining portion and the wide portion.